Many designs of optical fiber sensors are known (Zeitschrift fuer Labortechnik, October 1980, pages 1083 to 1093, or "Laser und Optoelektronik", No. 1984, pages 17 to 29); these, however, are primarily suited for the highly accurate resolution of small distance or angle quantities to the extent that they are suited for distance or angle measurements.
On the other hand, reference-value transmitters are known, with which larger distances or angles are possible and in which the motion of a distance or angle pickup is converted into an electrical signal, for instance, according to the potentiometer principle.
Finally, optical methods for determining larger distances or distance changes are known, in which a light pulse is transmitted, is reflected by the object to be measured, and the reflected pulse is received again. The propagation time of the transmitted and reflected pulse is a measure for the distance from the reflecting object.